1. Technical Field
The disclosure relates to a vehicle antitheft system and a vehicle security device which is used for the system.
2. Description of Related Art
For example, Japanese Patent Application Publication No. 2010-042754 (JP 2010-042754 A) and Japanese Patent Application Publication No. 2012-011876 (JP 2012-011876 A) disclose various measures against vehicle theft using an illegally taken regular vehicle key when a suspicious person such as a thief illegally takes the regular vehicle key (which includes a duplicated vehicle key of the regular vehicle key).